How to adjust layout when soft keyboard appears

This question has beeen asked a few years ago and "Secret Andro Geni" has a good base explanation and "tir38" also made a good attempt on the complete solution, but alas there is no complete solution posted here. I've spend a couple of hours figuring out things and here is my complete solution with detailed explanation at the bottom:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="10dp">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_above="@+id/mainLayout"
            android:layout_alignParentTop="true"
            android:id="@+id/headerLayout">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:gravity="center_horizontal">

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:id="@+id/textView1"
                    android:text="facebook"
                    android:textStyle="bold"
                    android:ellipsize="marquee"
                    android:singleLine="true"
                    android:textAppearance="?android:attr/textAppearanceLarge" />

            </LinearLayout>

        </RelativeLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:id="@+id/mainLayout"
            android:orientation="vertical">

            <EditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/editText1"
                android:ems="10"
                android:hint="Email or Phone"
                android:inputType="textVisiblePassword">

                <requestFocus />
            </EditText>

            <EditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="10dp"
                android:id="@+id/editText2"
                android:ems="10"
                android:hint="Password"
                android:inputType="textPassword" />

            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="10dp"
                android:id="@+id/button1"
                android:text="Log In"
                android:onClick="login" />

        </LinearLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_below="@+id/mainLayout"
            android:id="@+id/footerLayout">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true">

                <RelativeLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:id="@+id/textView2"
                        android:text="Sign Up for Facebook"
                        android:layout_centerHorizontal="true"
                        android:layout_alignBottom="@+id/helpButton"
                        android:ellipsize="marquee"
                        android:singleLine="true"
                        android:textAppearance="?android:attr/textAppearanceSmall" />

                    <Button
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentRight="true"
                        android:id="@+id/helpButton"
                        android:text="\?"
                        android:onClick="help" />

                </RelativeLayout>

            </LinearLayout>

        </RelativeLayout>

    </RelativeLayout>

</ScrollView>

And in AndroidManifest.xml, don't forget to set:

android:windowSoftInputMode="adjustResize"

on the <activity> tag that you want such layout.

Thoughts:

I've realized that RelativeLayout are the layouts that span thru all available space and are then resized when the keyboard pops up.

And LinearLayout are layouts that don't get resized in the resizing process.

That's why you need to have 1 RelativeLayout immediately after ScrollView to span thru all available screen space. And you need to have a LinearLayout inside a RelativeLayout else your insides would get crushed when the resizing occurs. Good example is "headerLayout". If there wouldn't be a LinearLayout inside that RelativeLayout "facebook" text would get crushed and wouldn't be shown.

In the "facebook" login pictures posted in the question I've also noticed that the whole login part (mainLayout) is centered vertical in relation to the whole screen, hence the attribute:

android:layout_centerVertical="true"

on the LinearLayout layout. And because mainLayout is inside a LinearLayout this means that that part does't get resized (again see picture in question).

Just add

android:windowSoftInputMode="adjustResize"

in your AndroidManifest.xml where you declare this particular activity and this will adjust the layout resize option.

some source code below for layout design

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="FaceBook"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="30dp"
        android:ems="10"
        android:hint="username" >

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/editText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText1"
        android:layout_marginTop="20dp"
        android:ems="10"
        android:hint="password" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText2"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="18dp"
        android:layout_marginTop="20dp"
        android:text="Log In" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginTop="17dp"
        android:gravity="center"
        android:text="Sign up for facebook"
        android:textAppearance="?android:attr/textAppearanceLarge" />

</RelativeLayout>